From: Christian Göttsche <cgzones@xxxxxxxxxxxxxx>
Introduce an ebitmap function to calculate the highest set bit.
Signed-off-by: Christian Göttsche <cgzones@xxxxxxxxxxxxxx>
---
security/selinux/ss/ebitmap.c | 27 +++++++++++++++++++++++++++
security/selinux/ss/ebitmap.h | 1 +
2 files changed, 28 insertions(+)
diff --git a/security/selinux/ss/ebitmap.c b/security/selinux/ss/ebitmap.c
index cd84357db2c4..74686b8a4c35 100644
--- a/security/selinux/ss/ebitmap.c
+++ b/security/selinux/ss/ebitmap.c
@@ -257,6 +257,33 @@ int ebitmap_contains(const struct ebitmap *e1, const struct ebitmap *e2,
return 1;
}
+u32 ebitmap_highest_set_bit(const struct ebitmap *e)
+{
+ const struct ebitmap_node *n;
+ unsigned long unit;
+ u32 pos = 0;
+
+ n = e->node;
+ if (!n)
+ return 0;
+
+ while (n->next)
+ n = n->next;
+
+ for (unsigned int i = EBITMAP_UNIT_NUMS; i > 0; i--) {
+ unit = n->maps[i - 1];
+ if (unit == 0)
+ continue;
+
+ pos = (i - 1) * EBITMAP_UNIT_SIZE;
+ while (unit >>= 1)
+ pos++;
+ break;
+ }
+
+ return n->startbit + pos;
+}
+
int ebitmap_get_bit(const struct ebitmap *e, u32 bit)
{
const struct ebitmap_node *n;
diff --git a/security/selinux/ss/ebitmap.h b/security/selinux/ss/ebitmap.h
index e0150695566c..99a21d83a0b3 100644
--- a/security/selinux/ss/ebitmap.h
+++ b/security/selinux/ss/ebitmap.h
@@ -126,6 +126,7 @@ int ebitmap_and(struct ebitmap *dst, const struct ebitmap *e1,
const struct ebitmap *e2);
int ebitmap_contains(const struct ebitmap *e1, const struct ebitmap *e2,
u32 last_e2bit);
+u32 ebitmap_highest_set_bit(const struct ebitmap *e);
int ebitmap_get_bit(const struct ebitmap *e, u32 bit);
int ebitmap_set_bit(struct ebitmap *e, u32 bit, int value);
void ebitmap_destroy(struct ebitmap *e);
--
2.45.2
